What is Glaucoma?
Typically, glaucoma is an eye condition that develops when too much pressure builds up inside the eye. It tends to be inherited and may not show up until later in life. The increased pressure, called intraocular pressure (IOP), can damage the optic nerve, which transmits images to the brain. If damage to the optic nerve from high IOP continues, glaucoma will cause loss of vision. Without treatment, glaucoma can cause total, permanent blindness.
There are two main types of glaucoma: open-angle glaucoma and angle-closure glaucoma. Open-angle glaucoma is the most common type of glaucoma. The structures of the eye appear normal, but fluid in the eye does not flow properly through the eye's filter, called the trabecular meshwork.
Angle-closure glaucoma, also called acute or chronic angle-closure or narrow-angle glaucoma, is less common than open-angle glaucoma, but can cause a sudden build-up of pressure in the eye. Drainage may be poor because the angle between the iris and the cornea (where a drainage channel for the eye is located) is too narrow.
Globally, glaucoma is the second leading cause of blindness, affecting 6.7 million people in 2000. Worldwide, an estimated 66.8 million people have glaucoma, and most are not even aware of it. That number is predicted to grow past 80 million by 2020. (WHO Report 2002)
What are the Symptoms of Glaucoma?
For most people, there are few or no symptoms of glaucoma. The first sign of glaucoma is often the loss of peripheral or side vision, which can go unnoticed until late in the disease. Detecting glaucoma early is one reason you should have a complete exam from an eye specialist every year. Occasionally, IOP can rise to severe levels. In these cases sudden eye pain, headache, blurred vision, or the appearance of halos around lights may occur.
If you have any combination of the following symptoms, contact your physician immediately:
Seeing halos around lights
Narrowing of vision (tunnel vision)
Vision loss
Redness in the eye
Eyes that look hazy
Nausea or vomiting
Pain in the eye
Who Does Glaucoma Affect?
Glaucoma most often occurs in adults over age 60, but it can also occur in young adults or children and is more common in those of African descent. In addition, if you have a history of glaucoma in your family, have poor vision (in particular, are severely nearsighted or shortsighted) or diabetes, you are at a greater risk of developing glaucoma than those individuals who do not.
How to Avoid the Progression of Glaucoma
Most of the risk factors such as age, race, and genetics for glaucoma are beyond your control. However, because most people with glaucoma have no early symptoms or pain from this increased pressure, it is important to see your ophthalmologist regularly so that glaucoma can be diagnosed and treated before long-term vision loss occurs. If there is a history of glaucoma in your family or if you have other risk factors for glaucoma more frequent exams may be necessary. Wear protective eye gear when necessary to avoid blunt trauma to the eye, which can cause traumatic glaucoma.